Non-mechanical tie-down means for inflatable tents or shelters



Feb. 23, 1965 w. w. CUSHMAN 3,170,472

NON-MECHANICAL TIE-DOWN MEANS FOR INFLATABLE TENTS OR SHELTERS Filed Aug. 30, 1962 INVENTOR. Q/alhvz w. Gus/Imam United States Patent 3,170,472 NON-MECHANICAL TIE-DOWN MEANS FOR INFLATAhLE TENTS GR SHELTERS Walton W. Cushman, 6428 Lumar Drive SE, Washington, D.C.

Filed Aug. 30, 1962, Ser. No. 220,967 10 Claims. (Cl. 135-Il) (Granted under Title 35, US. Code (1952), sec. 266) The invention described herein,'if patented, may be manufactured and used byand for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to inflatable tents or shelters and has for its primary objectto provide an extremely light and non-mechanical means for holding the shelter to the ground, not only while it is being inflated but also during the entire period of its use.

A further object of the invention consists in providing a tie-down for a shelter which will automatically provide a uniform pull throughout the entire periphery of the shelter.

Another object of the invention resides in the provision of a vacuum which is applied to the lower edge of the side wall of an inflatable shelter to hold the same in proper relation to the ground.

A further object of the invention consists in providing a downwardly-opening pocket in the lower edge of the shelter in which the vacuum is to be created.

A still further object of the invention consists in providing an endless inflated member adapted to be placed in the downwardly-opening pocket for maintaining the latter in partly distended condition while the vacuum is being applied and during the period of its use.

Another object of the invention resides in the combination with an inflatable shelter and vacuum type tiedown of a pump automatically controlled to simultaneously maintain the inflation and the tie-down feature.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings, in which FIGURE 1 is a side elevational view, partly broken away, of a semi-spherical inflated tent provided with the vacuum type tie-down embodying the present invention and showing in end elevation the combined mechanism for inflating the tent and for creating the vacuum;

FIGURE 2 is an enlarged fragmentary plan view of the tent shelter of FIGURE 1;

FIGURE 3 is a considerably enlarged fragmentary sectional view through the shelter and combined mechanism, illustrating in greater detail the vacuum type tie-down and the combined pumping mechanism for automatically infiating the shelter and producing and maintaining both the required vacuum and the necessary pressure within the .shelter, and showing, in broken lines, the parts in shelter erected and inflated positions and in full lines, the various parts in shelter deflating positions; 7

FIGURE 4 is an enlarged fragmentary perspective view of the base-forming member of the preceding view; and

FIGURE 5 is an enlarged fragmentary sectional view, partly in elevation, showing in detail the relationship of the tie-down base member with its external surface of scrim, the shelter wall flaps and the adjacent end portion of the suction manifold.

Before explaining in detail-the present invention, it is to be understood that the invention is not limited in its 3,17,472 Patented Feb. 23, 1965 ICC application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practiced or carried out in various Ways. It is to be understood also that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

With particular reference to the drawings, there is shown therein an inflatable shelter or tent having new and novel non-mechanical tie-down ineans for holding the shelter firmly to the ground, not only while itis being inflated but also during the entire period of its use, said means automatically providing a uniform pull throughout the entire periphery of said shelter. The shelter is shown as a whole at iii and, merely by way of illustration, is of hemispherical form, as can best be seen in FIG- URE 1.

The shelter it) may be formed from any suitable light weight air-impermeable flexible fabric material, the peripheral edge of which has aifixed thereto, in any suitable manner, a skirt consisting of two like ground flaps formed from strips or bands ll. and 12 of an elastomer, such as rubber, or the like, see particularly FIGURE 3. As may be seen in this View, the skirt portions 11 and 12 are spread out over the ground in opposite radial directions so as to form a tent-like arrangement which is adapted to overlie and straddle a previously-positioned base-forming member '13 which, as shown, is three-sided and of triangular cross section. It is formed from an impermeable material, such as packaging scrim, which is usually composed of polyethylene and some synthetic fabric such, for example, as nylon scrim. In the present instance the scrim is on the outside. It is to be understood that the member 13 is placed on theground preferably in the form of a circle andinflated sufficiently to take shape and receive and support the shelter skirt portions or flaps l1 and 12, see FIGURE 3. Instead of being inflated and for the purpose of increasing the effective joining area of the fiaps ll, 12 with the member 13, the latter may be filled, or partially filled with some suitable filler material, such as plastic foam, wood, cork, or the like so as to provide the member 13 with a more or less rigid surface. By making the outer side surfaces of the insert 13 slightly concave, not only do they present a larger area but they provide a better grip.

As shown in the drawings, particularly in FIGURE 3 thereoflcombined means is provided for erecting the shelter 19 andfor maintaining it in erected condition, as well as for holding it to the ground or other surface'upon which it is placed. Such means is a motor-driven combined air andvacuum pump assembly which, as shown, comprises a base 14, a pump 15 mounted upon the base, and an electric motor 9, also mounted upon base 14, for driving the pump 15.

The blower or discharge side of rotary pump 15 has connected to an upper portion of the housing thereof, a manifold, pipe, or conduit 16 whose outer free end is connected, in any suitable manner, to the adjacent wall of shelter it) in such a manner as to register with a port or opening Na formed in said wall. Interiorly of said Wall, the opening is controlled by a hinged cover preferably in the form of a flap'valve 17 which, should the operation of the pump be discontinued, will automatically close opening Mia and thus prevent the escape of air pressure from within the shelter.

Also connected to the housing of pump 15, at the intake forced or pressed against the ground by air pressure.

the absence of any insert such as 13, and in the absence of any anchoragefor the free edges of the flaps 11 and or suction side thereof, is a suction manifold, pipe, or conduit 18 having an elbow or curved portion 19 and terminating in a straight end portion 20. The latter. ex-

tends or projects through a hole or opening formed in flap 7 in the-elbow portion 19 of the suction conduit 18 is a gravity seated ball check valve 21, shown in FIGURE 3. By creating a partial vacuum in the spaces 13a, the nor-' mal air pressure on both sides of flaps 11 and 12 becomes unbalanced and such flaps are forced against the preferably scrim-covered sides of the triangular base-forming member 13 while the base of said member is in turn In edge portions of said flaps The smoother and more im pervious the surface upon which these horizontal free edges rest, the less leakage there is. For example, smooth mud, snow, ice, or relatively smooth concrete, make the best supporting surfaces or bases, while pervious surfaces,

such as sand and gravel, make the worst. The shelter,

or structure was the present invention will, however,

function or operate upon such last-named pervious sur-, facesbut the pump must be worked harder. By virtue of the use of the present novel base-forming member,

or insert .13, the need for employing a conventional and However, by using an valve 23 will break the vacuum in space 13:: so that shelter 10 when deflated, or partially deflated, can be lifted oii and separated from contact with the base-forming member 13. When this condition exists, the shelter can be completely collapsed and transported to another location, or placed in storage, as required.

It is to be understood, of course,.that the electric motor 9 derives its current from a suitable source of supply through wires or cables 9a seen in FIGURE 2. It will also be understood that the operation of the rotary pump assembly may be controlled manually, automatically, or semi-automatically, as desirable. Under normal conditions of use, the pump 15 is operated intermittently simply. to maintain the proper, pressure to. keep the shelter 1th in its erected condition. -When the pump is not in operation, pressure inside the shelter or enclosure 19 closes the flap valve 17- and prevents escape of air pressure through wallopening Illa.

I claim:

1. In a shelter adapted to be inflated into its erected condition, a downwardly-opening inverted substantially V-shaped pocket, an inflatable member of substantially triangular cross-section inserted in said pocket, and mechanism associated with the shelter for inflating the same and forcreating a partial vacuum in said pocket.

2. A shelter according to claim 1, wherein said inflatable memberincludes upwardly converging side walls' having outer surfaces which are concave in vertical cross section.

3. Ina shelter assembly adapted to be inflated into its erected condition, a downwardly-opening inverted substantially V-shaped pocket, an inflatable member whose body is of substantially triangular cross-section inserted in said pocket, means disposed on the external surface of said body and engageable' with said V-shaped pocket for spacing the walls of the pocket from the body of the expensive continuous sealing ring, or anchor, heretofore used with conventional inflatable structures to provide an adequate seal with the base surface, is entirely eliminated. Moreover, the infiatable'structure or tent 16 can be erected in considerably less time and with fewer personnel than previously known structures in the same category.

By disposing or locating the scrim on the outer surfaces of the base-forming member or insert13, the threads of effect the space or spaces 13a bestseen in FIG. 4, when vacuumized. This allows the partial vacuum to be drawn from the entire area of space 13a instead of limiting it to an area which corresponds to the size of the mouth of the end portion 20 of the pipe or conduit 18 (FIG- URE 3).

The, underside of suction conduit 18 is provided with a valve seat 22 which is adapted to receive a conical valve 23. The valve 23, see FIGURE 2, is carried by the offset port1on 25 of a valve control arm or lever 24 which is swingably mounted or supported at 26 upon the pump assembly base 14. The valve-supporting arm or actuator V '24 1s proportioned as to size, length and weight so as to the inherent coarse weave of this fabric serve to space the 4 inner or under surfaces of the flaps 11 and 12 slightly from the adjacent surfaces of member 13, providing in have its free end positioned normally in frictional en- V gagement or contact with the adjacent portion of the band or flap 12 of the shelter so that upward movement of the shelter during inflation thereof and the creation of a the cover skin orfabric moves down toward a deflated condition, frictional engagement thereof with the contacting .end of arm 24 will cause or allow the arm to "move downward about its'pivot Z6, unseating the valve 2 3, thus opening the suction side of the rotary pump 15 to atmosphere, as seen in FIGURE 3. This opening of 7 construction.

inflatable member,- and means forming a part of said shelter assembly for creating a partial vacuum in said pocket. j

4. In combination, an inflatable shelter, a downwardlyopening pocket attached to the lower edge of the side-. walls of the shelter adapted to be vacuumized to provide a tie-down for the shelter, a three-sided base-forming member of triangular cross sectionwithin said pocket, a 'motor-operated pump for continuously inflating the shelter and maintaining the vacuum, said pump having an air intake opening into said pocket as well as an air outlet opening into said shelter, and said pump including an automatically operated valve for shifting the intake of the pump from the pocket to the atmosphere and vice operative to allow said valve arm to move to a position opening said valve to the atmosphere. I

6. The combination of claim 4, wherein said pocket is of inverted V-shaped in cross section, a substantially complementary insert in said pocket, andsaid insert being of substantially rigid construction.

7. In a shelter adapted to be inflated into an erected position, said shelter including an endless .side wall having a lower edge formed of inner and outer flexible flaps providing a pocket which is of inverted V-shape in cross section, an endless insert having a cross sectional shape complementary to said pocket. and inserted therein to substantially fill the same, and means for'creating a partial vacuum in said pocket between said flaps andsaid insert. 7

8.. A shelter according, to claim 7, wherein said insert has upwardly converging side walls of substantially rigid 9. A shelter adapted to be inflated into its erected position, said shelter having an endless side wall including a lower edge formed with a downwardly opening pocket defined by flexible side walls, said side walls having laterally directed free edge portions, an inverted V-shaped insert substantially filling said pocket between said later ally directed edge portions, said insert being substantially rigid, and means for creating a partial vacuum in said pocket.

10. A shelter according to claim 9, wherein said insert comprises upwardly converging side walls which are concave in cross section.

References Cited by the Examiner UNITED STATES PATENTS Mills 103-40 X Stenger 10340 X Livers 10340 X Hotz 135-1 Turner 135--1 Hoffman 1351 HARRISON R. MOSELEY, Primary Examiner.

CHARLES OCONNELL, Examiner. 

1. IN A SHELTER ADAPTED TO BE INFLATED INTO ITS ERECTED CONDITION, A DOWNWARDLY-OPENING INVERTED SUBSTANTIALLY V-SHAPED POCKET, AN INFLATABLE MEMBER OF SUBSTANTIALLY TRAINGULAR CROSS-SECTION INSERTED IN SAID POCKET, AND MECHANISM ASSOCIATED WITH THE SHELTER FOR INFLATING THE SAME AND FOR CREATING A PARTIAL VACUUM IN SAID POCKET. 